For example, in a conventional terminal floor deceleration unit for an elevator disclosed in JP-A 58-6885, when a terminal detector operates, a terminal floor deceleration command signal is generated according to the distance from a position at the time when the terminal detector operates to a terminal floor. Such a terminal floor deceleration command signal is generated through a calculation by a digital calculator.
However, when an attempt is made to use a computer to perform various calculations for safety surveillance and commands regarding abnormalities, for example, the surveillance of an overspeed and the surveillance of a break in a rope as well as the surveillance of the position of a car by the terminal floor deceleration unit, the capacity of a RAM used for the calculations needs to be increased, and a program in the computer may run out of control. When the program runs out of control, operation control of the elevator also suffers an abnormality. This may damage components of the elevator.